Fuel injection nozzle



p -5 1967 E. J. GHGER V 3,339,848

FUEL INJECTION NOZZLE Filed Oct. 20, 1965 2 Sheets-Sheet 2 'INVENTOR EUGENE J. GEIGER United States Patent M 3,339,848 FUEL INJECTION NOZZLE Eugene J. Geiger, Dearborn, MiclL, assignor to International Harvester Company, Chicago, 11]., a corporation of Delaware Filed Oct. 20, 1965, Ser. No. 498,297 6 Claims. (Cl. 239-453) This invention relates to improvements in fuel injection nozzles for internal combustion engines.

A particular object of the invention is the provision in such a nozzle of a fine pilot injection into the combustion chamber preliminary to full operating injection in order to facilitate the starting of the engine, gradually warmingi t, thereby avoiding unnecessary smoke load due to inefficient combustion, fuel waste and engine deterioration.

Hence, the invention generally comprises a nozzle structure adopted for the initial introduction of fuel into the nozzle at a relatively low pressure (e.g., 1500 p.s.i.) whereupon a poppet valve will open for the injection of a relatively fine stream of fuel into the combustion charnher, and thereafter upon increase of fuel pressure to a predetermined value (e.g., 2500 p.s.i.), a differential needle valve will open for the injection of a full stream of fuel into that chamber, at which time the poppet valve closes correspondingly with the opening of the needle valve.

A further object of the invention is the provision of a fuel injection nozzle assembly which combines the operating characteristics of an outwardly opening poppet valve and a differential needle valve hole type nozzle.

Another object of the invention is the provision of such a nozzle assembly in which such valves are cooperatively arranged in highly advantageous generally tandem relation.

Other objects and advantages of the invention will appear as the description of it proceeds in relation to the accompanying drawings in which:

FIG. 1 is a central longitudinal section of an embodiment of the invention with the parts in inoperative position;

FIG. 2 is a similar section with the parts in first position of operation;

FIG. 3 is a similar section with the parts in second position of operation; and

FIG. 4 is a cross-section along the line 4-4 of FIG. 3.

Referring to the drawings the nozzle comprises a body llvwhich, for convenience of manufacture, includes co-axial front and rear sections 12, 14 suitably secured together.

Body section 12 has a forward portion 12a of reduced cross-section and a central longitudinally extending bore 13 for receiving movable parts of a poppet valve assembly 15 and differential needle valve assembly 16 in generally co-axial relation with one another.

Bore 13 has an enlarged rearward portion 13a, and a restricted forward portion or throat 13b, which terminates in an outwardly flaring orifice forming a seat 15a for poppet valve member 15b; bore 13 tapering toward throat 13b to form a seat 16a for needle valve member 16b.

.Generally. cylindrical needle valve member 16b has a truncated, generally conical forward extremity or nose 16c receivable in valve seat 16a and an enlarged rearward end portion 16d slidable in enlarged rearward portion 13a of bore 13.

Rear body section 14 has a central bore 14a extending longitudinally thereof and co-axial radially co-extensive, and in open communication, with bore portion 13a.

3,339,848 Patented Sept. 5, 1967 Needle valve member 16b has a central bore 16e for receiving poppet valve stem 150 in slidable relation coaxially therewith; bore 16e being enlarged adjacent the rearward extremity of member 16b to provide a recess 16 for receiving a spring 15d carried by valve stem 15c co-axially therewith; valve stem 15c extending rearwardly of valve member 16b and having adjustably mounted thereon adjacent its rearward extremity a collar 15'e of greater diameter than recess 16f.

Bore 14a is arranged to receive a spring 14d co-axially therewith, spring 1411 being disposed in abutting relation at one end thereof with the rearward extremity of valve member 161), and at the other end thereof with a closing member or stop 14c, adjustably arranged in bore 14a adjacent its rearward extremity.

Springs 14d and 15a and the parts associated therewith are so conformed and arranged to operate that when nozzle 10 is inoperative valve assemblies 15 and 16 and the respective parts thereof will be in the position shown in FIG. 1, poppet valve member 15b being seated in closed position in relation to seat 15a; needle valve member 16b having its nose 16c seated in closed position in relation to valve seat 16a; collar 15a being in predetermined spaced relation with rearward end portion 16d of needle valve member 16b and end portion 16d being correspondingly spaced from the shoulder 130 of bore portion 13a.

Fuel under pressure is applied to nozzle 10 through duct 20 extending longitudinally of body 11, and terminating in a transverse portion 21 arranged circumferentially of bore 13 and in communication with a plurality of flats or duct 22 (FIG. 4) for-med intermediately of cutaway portions 23 of needle valve member 16b and opposed walls of bore 13 and extending longitudinally thereof and in spaced relation with one another. Flats 22 terminate in communication with throat 13b and transverse passages 2211 which comunicate with chamber 24 disposed centrally of the truncated nose 160 of valve member 16b, chamber 24 being radially coextensive and in open communication with throat 13b. The dimensions of chamber 24, throat 13b and poppet valve member 15b and the bias of springs 14d, 15d are related to the applicable fluid pressure and the desired output.

Needle valve orifice 25 is conformed and arranged to provide the desired fuel out-put at full operating pressure when poppet valve member 15b is in the operated position of FIG. 3.

Peripheral cutaway portion 16g of needle valve member 16b provides a cushioning reservoir 25a limiting return movement of needle valve member 16b While accommodating leak oft. Leak off provision is made also in the spacing of end portion 16d in relation to shoulder 13c and ducts 26 provided in stop 14e.

Nozzle 10 and its component parts are arranged to operate in the steps illustrated in FIGS. 1, 2 and 3. The parts being in the inoperative position of FIG. 1, upon the introduction of fuel under predetermined pressure (e.g. 1500 p.s.i.) overcoming the bias of spring 15d, poppet valve 15 will operate to the position of FIG. 2 to provide a preliminary, relatively mild stream of fuel for combustion thereby enabling a gradual warming of the engine. It will be noted that in this operation forward movement or projection of valve member 15b is limited by abutment of collar 152 against the enlarged rear end portion 16d of needle valve member 16b, movement of which also is restricted by the seating of its nose portion in seat 16a.

Thereafter upon increasing the pressure of the fuel supply to a higher predetermined value (e.g. 2500 p.s.i.) and the further building up of pressure in the system,

including chamber 34, overcoming the bias of spring 14d, needle valve member 16b will shift to the position of FIG. 3, and its rear end portion 16d abutting collar 152, the latter and poppet valve member 1511 likewise shifting to the position of FIG. 3. And the higher fuel pressure being continued the parts will remain in the position of FIG. 3 for the introduction of full fuel supply to the associated combustion chamber.

The parts return to the position FIG. 1 upon the withdrawal of the pressure with this variation, namely, that due to the differential character of the needle valve, the poppet valve member 15 is retained in its closed position of FIG. 3 until needle valve member 16b shall have shifted to closed position in seating relation with seat 16a as in FIG. 1.

It will be understood that changes in form and structure from the foregoing description may be made without departing from the spirit of the invention as set forth in the claims which follow.

I claim:

1. A fuel injection nozzle for an internal combustion chamber comprising (a) a nozzle body having a central bore extending longitudinally thereof,

(b) a valve assembly operatively arranged in said bore and including,

(c) a differential needle valve assembly and a poppet valve assembly arranged in generally tandem relation with one another with their respective valve members arranged in limited mutual sliding relation to and fro along the longitudinal axis of said bore,

((1) said bore tapering to an anterior throat portion thereby forming a seat for said needle valve member,

(e) a main fuel ejection orifice in operative communication with said tapering bore portion,

(f) said needle valve member having a generally frustoconical nose portion receivable in said seat in valveclosing relation,

(g) said throat portion flaring generally outwardly to a pilot fuel ejection orifice forming a seat for said poppet valve member,

(h) said valve members being differentially springbiased in valve seated position closing said orifices,

(i) a central recess in said nose portion of said needle valve member forming a fuel pressure chamber, in operative communication with said throat portion and said orifices,

(j) a fuel supply system comprising a plurality of passages arranged in operative communication with said chamber and said throat portion for delivering a supply of fuel under pressure thereto,

said valve assemblies and their associated parts being so conformed and arranged to operate whereby upon fuel being supplied to said system under pressure, said valve members being seated and said orifices being closed, at a predetermined fuel pressure in said chamber said poppet valve assembly will operate to shift said poppet valve member to a projected second position, opening said pilot fuel ejection orifice thereby to inject a pilot stream of fuel into an associated combustion chamber,

and thereafter at a predetermined higher fuel pressure in said chamber said needle valve assembly will operate to shift said needle valve member to a retracted, second position, opening said main fuel orifice and retracting said poppet valve member to its first position closing said pilot orifice, thereby to inject a main stream of fuel into such combustion chamber,

and subsequently upon the reduction of the fuel pressure in the system in a predetermined amount, said needle valve assembly will operate to project said needle valve member, closing said main orifice, said pilot orifice remaining closed.

2. A fuel injection nozzle according to claim 1 in which the needle valve member has a peripheral cutaway portion in predetermined spaced relation with the forward extremity of the nose portion of said valve member and with the proximate surface of said tapering bore portion and providing a fuel cushioning reservoir limiting return of said needle valve member from a position of retraction to valve seated position.

3. A fuel injection nozzle according to claim 2 in which the fuel supply system comprises (a) a main supply duct arranged for operative communication with a source of fuel supply under pressure under operator control,

(b) a distributor duct communicating with said main supply duct,

(c) a plurality of peripheral flats extending longitudinally of said needle valve member in circumferentially spaced relation with one another and with the proximate surface of said bore, and being in operative communication with said distributor duct and with said throat position,

(d) a plurality of top ducts in said needle valve member and operatively interconnecting said flats and said chamber.

4. A fuel injection nozzle according to claim 2 in which said fuel cushioning reservoir is in open communication with said chamber and said throat portion when said needle valve member is in retracted, valveopen position and is cut off therefrom when said needle valve member is in projected, valve-closed position.

5. A fuel injection nozzle according to claim 1 including first stop means comprising means on said needle valve member and corresponding means interiorly of said body for limiting sliding movement of said needle valve member in one direction in relation to said bore, and second stop means comprising means connected with said poppet valve member and corresponding means on said needle valve member for limiting sliding movement of said poppet valve member in said one direction in relation to said needle valve member, said needle valve member and said poppet valve member being differentially spring-biased in the opposite direction.

6. A fuel injection nozzle for an internal combustion engine comprising (a) a generally cylindrical body,

(b) a generally central bore in said body extending longitudinally thereof, said bore having a rear section of relatively large diameter,

an intermediate section of reduced diameter, and

an anterior throat section of further reduced diameter,

(c) a differential needle valve assembly including a generally cylindrical needle valve member slidable to and fro in said bore longitudinally thereof and co-axially therewith,

said needle valve member having a central bore extending longitudinally therethrough,

(d) a poppet valve assembly including a poppet valve member having a stem slidable to and fro in the bore of said needle valve member co-axially therewith,

(e) first stop means comprising means on said needle valve member and corresponding means interiorly of said body, for limiting sliding movement of said needle valve member in one direction in relation to said bore,

(f) said needle valve member being spring-biased in a predetermined value in the opposite direction,

(g) second stop means comprising means on said poppet valve stem and corresponding means on said needle valve member, for limiting sliding movement of said poppet valve member in said one direction in relation to said needle valve member,

(h) said poppet valve member being spring-biased in said opposite direction in a predetermined lesser value,

(i) said needle valve member having a generally frustoconical nose portion with a central recess therein co-axial, and radially co-extensive, with said throat section, and in operative communication therewith whereby to form a fuel pressure chamber,

(j) said intermediate bore section tapering toward said throat section whereby to provide a seat for said needle valve member in valve closing relation,

(k) said bore flaring outwardly from said throat section whereby to provide a pilot fuel ejection orifice and a seat for receiving said poppet valve member to close said orifice,

(l) a fuel supply system comprising a plurality of ducts for transmitting fuel under pressure through said nozzle including a main duct, a distributor duct in open communication with said main duct,

a plurality of flats extending longitudinally of said needle valve member, in spaced relation with one another circumferentially thereof and with the proximate surface of said intermediate bore section, and in operative communication with said distributor duct and with said throat section,

a plurality of tap ducts in said needle valve member and operatively interconnecting said flats and said fuel pressure chamber,

(m) a main fuel ejection orifice in predetermined spaced relation with said pilot orifice and in operative communication with said fuel supply system under control of said needle valve assembly,

said nozzle and its component parts being so conformed and arranged to operate whereby upon fuel being supplied to said fuel supply system under pressure, said parts being in inoperative first position, both valve members being in closed position,

at a given fuel pressure in said chamber said poppet valve assembly will operate to shift said poppet valve member to a sec-0nd position opening said pilot orifice, whereby to inject a pilot stream of fuel into an associated combustion chamber, said needle valve assembly remaining inoperative,

and thereafter at a given higher fuel pressure in said chamber said needle valve assembly will operate to shift said needle valve member to a retracted second position opening said main orifice and retracting said poppet valve member member to its first position closing said pilot orifice,

and subsequently upon the reduction of the fuel pressure in the system to a predetermined lower value said needle valve assembly will operate to project said needle valve member closing said main orifice, said pilot orifice remaining closed.

References Cited UNITED STATES PATENTS FOREIGN PATENTS 121,076 12/1918 Great Britain.

EVERETT W. KIRBY, Primary Examiner. 

1. A FUEL INJECTION NOZZLE FOR AN INTERNAL COMBUSTION CHAMBER COMPRISING (A) A NOZZLE BODY HAVING A CENTRAL BORE EXTENDING LONGITUDINALLY THEREOF, (B) A VALVE ASSEMBLY OPERATIVELY ARRANGED IN SAID BORE AND INCLUDING, (C) A DIFFERENTIAL NEEDLE VALVE ASSEMBLY AND A POPPET VALVE ASSEMBLY ARRANGED IN GENERALLY TANDEM RELATION WITH ONE ANOTHER WITH THEIR RESPECTIVE VALVE MEMBERS ARRANGED IN LIMITED MUTUAL SLIDING RELATION TO AND FRO ALONG THE LONGITUDINAL AXIS OF SAID BORE, (D) SAID BORE TAPERING TO AN ANTERIOR THROAT PORTION THEREBY FORMING A SEAT FOR SAID NEEDLE VALVE MEMBER, (E) A MAIN FUEL EJECTION ORIFICE IN OPERATIVE COMMUNICATION WITH SAID TAPERING BORE PORTION, (F) SAID NEEDLE VALVE MEMBER HAVING A GENERALLY FRUSTTOCONCIAL NOSE PORTION RECEIBABLE IN SAID SEAT IN VALVECLOSING RELATION, (G) SAID THROAT PORTION FLARING GENERALLY OUTWARDLY TO A PILOT FUEL EJECTION ORIFICE FORMING A SEAT FOR SAID POPPET VALVE MEMBER, (H) SAID VALVE MEMBERS BEING DIFFERENTIALLY SPRINGBIASED IN VALVE SEATED POSITION CLOSING SAID ORIFICES, (I) A CENTRAL RECESS IN SAID NOSE PORTION OF SAID NEEDLE VALVE MEMBER FORMING A FUEL PRESSURE CHAMBER, IN OPERATIVE COMMUNICATION WITH SAID THROAT PORTION AND SAID ORIFICES, 